Presentation on theme: " Content: We will learn about magnetic properties. Language: We will read new information about the Earths magnetosphere. We will classify prior knowledge."— Presentation transcript:
Content: We will learn about magnetic properties. Language: We will read new information about the Earths magnetosphere. We will classify prior knowledge in our notes and confirm our understanding of magnetism.
Magnetism ◦ the phenomenon of physical attraction for iron observed in magnets, inseparably associated with moving electricity and characterized by fields of force Magnetic force increases as magnets move closer together!
A magnetic field surrounds a magnet and is strongest at the poles; it is produced by the motion of electric charge. Both the orbital & spinning motion of every electron in an atom produce magnetic fields.
Magnetic field lines: arrows drawn from north to south poles representing the magnetic field. Number of field lines indicates the relative strength of the magnet
All magnets have a north pole and a south pole Like poles repel. Unlike poles attract
A compass needle is a small bar magnet that can freely rotate A compass needle always points north, or rather is north-seeking
Material that keeps its magnetic properties, even when it is not close to other magnets Made by placing a magnetic material in a strong magnetic field, which causes the domains to remain aligned.
The domains of temporary magnets are only aligned when the material is influenced by a magnetic field. (ex. Refrigerator, white board)
Electromagnet – temporary magnet that is created by electric current flowing in a wire, usually in the form of a wire coiled around a piece of iron Magnetic field is present only when current is flowing in the wire coil
Strength of an electromagnet depends on: amount of current in the wire amount of iron or steel in the core number of turns in the coil
Electromagnetic induction – the production of an electric current by moving a loop of wire through a magnetic field or moving a magnet through a wire loop (which changes the magnetic field near the conductor; no battery!)